This invention relates to hypofluorite compounds and to a novel method for their preparation. In a more particular manner, this invention concerns itself with an improved method for synthesizing pentafluorotellurium hypofluorite (TeF.sub.5 OF) which utilizes the direct fluorination of B(OTeF.sub.5).sub.3 with elemental fluorine.
Hypofluorite compounds are well known and find utility in a wide variety of industrial applications. They are especially useful as fluorinating agents for introducing fluorine atoms into another compound, and as intermediates in various synthetic reactions. Until recently no successful method was available for the synthesis of the unknown TeF.sub.5 OF although at least one unsuccessful attempt was made by Seppelt et al, Inorg. Chem., 1973, 12, 2727.
However, experimental efforts proved successful and a novel method for synthesizing TeF.sub.5 OF was discovered such as U.S. Pat. No. 4,462,975. It was found that it could be produced in stable form and in relatively high yield. The synthesis of this compound was achieved by a method which used fluorine fluorosulfate as a fluorinating agent. The method was carried out by effecting a reaction between CsTeF.sub.5 O and FOSO.sub.2 F at relatively low temperatures. This reaction represented a new route to the synthesis of hypofluorites but, unfortunately, it entailed certain drawbacks. Among these drawbacks was the need for careful low temperature control, long reaction times up to nine days and the requirement for excess CsTeF.sub.5 O together with less than optimum yields approximating 70%. Furthermore, the necessity to prepare and handle the treacherously explosive FOSO.sub.2 F was a decided disadvantage.
However, as the result of a continuing research effort it was found that a new and improved process for the synthesis of TeF.sub.5 OF could be accomplished by utilizing elemental fluorine and B(OTeF.sub.5).sub.3 as reactants at elevated temperatures. This new procedure provided TeF.sub.5 OF at a higher yield and with shorter reaction times than were achieved heretofore.